CVE-2026-63929

{"id": "CVE-2026-63929", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 5.5, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 1.8}]}, "affected": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "affectedData": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "3e26d9f08fbe0b73e951a5e810fdb7a332b7e37f", "lessThan": "9678aeed8b77d495a417dd057d479f3733094019", "versionType": "git"}, {"status": "affected", "version": "3e26d9f08fbe0b73e951a5e810fdb7a332b7e37f", "lessThan": "3412a95afaa5d3262008dfc34f3c7be33d8151dc", "versionType": "git"}, {"status": "affected", "version": "3e26d9f08fbe0b73e951a5e810fdb7a332b7e37f", "lessThan": "96cdeaba6a008503455b78a9641c05c2a886a7ec", "versionType": "git"}, {"status": "affected", "version": "3e26d9f08fbe0b73e951a5e810fdb7a332b7e37f", "lessThan": "a093999355084bdbfe6e97f1dd232e58a1525f0b", "versionType": "git"}], "programFiles": ["drivers/iio/industrialio-buffer.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "6.11"}, {"status": "unaffected", "version": "0", "lessThan": "6.11", "versionType": "semver"}, {"status": "unaffected", "version": "6.12.93", "versionType": "semver", "lessThanOrEqual": "6.12.*"}, {"status": "unaffected", "version": "6.18.35", "versionType": "semver", "lessThanOrEqual": "6.18.*"}, {"status": "unaffected", "version": "7.0.12", "versionType": "semver", "lessThanOrEqual": "7.0.*"}, {"status": "unaffected", "version": "7.1", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["drivers/iio/industrialio-buffer.c"], "defaultStatus": "affected"}]}], "published": "2026-07-19T16:17:11.277", "references": [{"url": "https://git.kernel.org/stable/c/3412a95afaa5d3262008dfc34f3c7be33d8151dc", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/9678aeed8b77d495a417dd057d479f3733094019", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/96cdeaba6a008503455b78a9641c05c2a886a7ec", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/a093999355084bdbfe6e97f1dd232e58a1525f0b", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "CWE-401"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\niio: buffer: Fix DMA fence leak in iio_buffer_enqueue_dmabuf()\n\niio_buffer_enqueue_dmabuf() allocates a struct iio_dma_fence (104 bytes,\nkmalloc-128) via kmalloc_obj()+dma_fence_init(), which sets the initial\nkref to 1. It then calls dma_resv_add_fence() which takes a second\nreference (kref=2), and stores a raw pointer in block->fence.\n\nOn the success path the function returns without calling dma_fence_put()\nto release the initial reference, so every buffer enqueue permanently\nleaks one kmalloc-128 allocation.\n\nThe iio_buffer_cleanup() work item only releases the temporary reference\ntaken during completion signalling by iio_buffer_signal_dmabuf_done();\nthe initial reference from dma_fence_init() is never released.\n\nWith four iio_rwdev instances at 240kHz and 512 samples per buffer,\nthis produces ~1875 kmalloc-128 allocations per second matching the\nobserved slab growth exactly. A test with ftrace confirmed that the\ndma_fence_destroy event was never triggered.\n\nFix by calling dma_fence_put() after dma_resv_add_fence(), transferring\nownership of the fence to the DMA reservation object. The DMA fence then\ngets properly discarded after being signalled."}], "lastModified": "2026-10-30T14:29:04.287", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "424D443C-A075-4671-94EC-F9F3E489E267", "versionEndExcluding": "6.12.93", "versionStartIncluding": "6.11"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "0FCCB23A-7629-4386-93B6-B119237C4382", "versionEndExcluding": "6.18.35", "versionStartIncluding": "6.13"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "9161A938-0FA8-44BC-95FE-C5A271601AB3", "versionEndExcluding": "7.0.12", "versionStartIncluding": "6.19"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "B1EF7059-E670-45F4-B422-54C40FA86390"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "0D38F0BF-A728-4133-A358-D44A2F7EE6D6"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "EC732D08-5F7B-46D9-B154-E60C7F4F0A97"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "E5910A9D-F60A-409A-B486-FE66BFEBA9B9"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "81DFF19E-9CF8-49C6-8C36-1E4038622933"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}